Documentation

LeanPool.ClassificationOfSurfaces.FiniteCyclicSignedRealization

Polygonal realization under signed presentation isomorphism #

A signed presentation isomorphism may rename and independently reverse edge names, relabel faces, and cyclically rotate each stored face word. This file realizes those operations geometrically. The selected cyclic rotation acts on the circular polygon carrier by an exact complex rotation, so every labelled source side is sent to the target side carrying its relabelled dart.

The resulting homeomorphism of polygonal pre-realizations transports both the elementary gluing generators and their equivalence closures. It therefore descends to a homeomorphism of the faithful polygonal quotients.

The rotateHomeomorph declaration.

Equations
  • One or more equations did not get rendered due to their size.
Instances For
    @[simp]
    theorem LeanEval.Topology.ClassificationOfSurfaces.PolygonCell.rotateIndex_val {n : } (hn : 0 < n) (k : ) (i : Fin n) :
    (rotateIndex hn k i) = (i + k) % n
    theorem LeanEval.Topology.ClassificationOfSurfaces.PolygonCell.rotateHomeomorph_side_of_eq {n m : } (h : n = m) (hm : 0 < m) (k : ) (i : Fin n) (t : unitInterval) :
    (rotateHomeomorph h k) ((side i) t) = (side (i + k) % m, ) t

    Rotation sends a side to the correspondingly shifted side after changing only the phantom side-count index.

    The target-boundary rotation selected for a signed presentation isomorphism.

    Equations
    Instances For

      The target side occupied by a source side after the selected face rotation.

      Equations
      Instances For

        The rotated target side carries exactly the relabeled source dart.

        A signed presentation isomorphism gives a facewise homeomorphism of polygonal pre-realizations.

        Equations
        Instances For

          On a labelled side, the pre-realization homeomorphism is exactly the selected cyclic shift.

          Transport a boundary occurrence through the selected cyclic shift.

          Equations
          Instances For

            A compatible source pairing transports to a compatible target pairing.

            Equations
            • One or more equations did not get rendered due to their size.
            Instances For

              Ignoring cyclic shifts, corresponding boundary-occurrence types have the same cardinality.

              Equations
              Instances For

                Pull a compatible target pairing back through the occurrence equivalence.

                Equations
                • One or more equations did not get rendered due to their size.
                Instances For

                  Signed edge relabeling, face relabeling, and cyclic boundary rotation preserve the faithful polygonal realization.

                  Equations
                  Instances For

                    Propositional realization-invariance form used by elementary-move closures.